Vitamin K controls the formation of prothrombin, factor VII, factor IX, and factor X by acting as a substrate for the enzyme γ-glutamyl carboxylase. This enzyme catalyzes the addition of carbon dioxide to the γ-carbon of protein-bound glutamic acid in the gla regions of the coagulation factors.
Coumarin anticoagulants, which include warfarin and dicumarol (dicoumarol), prevent the reduction of vitamin K epoxides in the liver microsomes and induce a state of vitamin K deficiency. A side effect of such anticoagulants is hemorrhage. If hemorrhage does occur, there is a need for a substance to inhibit the coumarin anticoagulant-induced bleeding.